Re: [PATCH] mm/page_alloc: return 0 in case this node has no page within the zone

[Andrew Morton]

On Mon,  6 Feb 2017 23:43:14 +0800 Wei Yang <richard.weiyang@xxxxxxxxx> wrote:

> The whole memory space is divided into several zones and nodes may have no
> page in some zones. In this case, the __absent_pages_in_range() would
> return 0, since the range it is searching for is an empty range.
> 
> Also this happens more often to those nodes with higher memory range when
> there are more nodes, which is a trend for future architectures.
> 
> This patch checks the zone range after clamp and adjustment, return 0 if
> the range is an empty range.

What are the user-visible runtime effects of this change?